The present invention relates to smoke-producing apparatus for detecting leaks.
Leak detection by using smoke-carrying air is known. For example, automobile mechanics have, for many years, used smoke-laden air pumped into a closed system, such as a radiator and engine coolant system, to find leaks. However, there is a need for devices that are lower cost, more reliable, non-complex, and that produce a more consistent smoke. Also, devices are needed that are adaptable for different uses, with different equipment and in different environments. In particular with automotive fuel and evaporative emissions testing, a smoke-producing apparatus is needed that does not leave a residue, and that produces a highly uniform and low-particle-size smoke.
Pieroni et al. U.S. Pat. No. 5,922,944 discloses an apparatus for simultaneously producing smoke and airflow. However, sometimes separate or independent control is needed, such as when more or less airflow is needed, or when denser (or less dense) smoke is needed or preferred. Further, there is a need for better control of the smoke during initial start-up of the apparatus and for more uniform smoke concentration, and also for control over fluid droplets going downstream. Also there is a need for remote control so that a mechanic doesn""t have to go back to tester unit to control it or to turn it off (or on).
Accordingly, an apparatus is desired having the aforementioned advantages and solving the aforementioned problems.
In one aspect of the present invention, an apparatus for generating smoke includes a closed chamber having an air inlet and an air outlet, an electric heating element positioned transversely in the chamber, and a supply of smoke-producing fluid. A dispenser is positioned over the electric heating element and operably connected to the supply of smoke-producing fluid, the dispenser being configured to spread and drop controlled quantities of the smoke-producing fluid onto the heating element. An air supply is connected to the air inlet, and a conduit is connected to the air outlet for communicating air from the air supply mixed with smoke generated by the heating element in the closed chamber to a location for use.
In another aspect of the present invention, an apparatus for testing for leaks includes a smoke-producing chamber, and a first control for controlling a quantity of smoke generated. An air supply is operably connected to the smoke-producing chamber, and a second control, independent of the first control, is provided for controlling flow of smoke from the smoke-producing chamber.
In another aspect, an apparatus for testing for leaks includes a smoke-producing device having a control for controlling a quantity of smoke generated and dispensed, the control including a receiver for receiving signals and being constructed to turn off the smoke-producing device upon receiving a shutoff signal. A remote control sender is provided and constructed to send the shutoff signal to the receiver.
In yet another aspect, an apparatus for generating smoke includes a closed chamber having a top cover, and an air inlet tube and an air outlet tube extending through the cover, at least one of the tubes being conductive. An electric coiled-wire heating element is positioned transversely in the chamber and operably electrically connected to the at least one conductive tube. A spray dispenser is attached to the top cover and positioned over the heating element and operably connected to a supply of smoke-producing fluid, the dispenser being configured to spread and drop controlled quantities of the smoke-producing fluid onto the heating element.